1. Field of the Invention
The present invention relates to a printing apparatus, and a control method and a storage medium therefor.
2. Description of the Related Art
Heretofore, there are known printing apparatuses such as electrophotographic printers (e.g., laser beam printer, LED printer, etc.) and electrophotographic copying machines. The electrographic printing apparatuses are each configured to irradiate light onto a photosensitive member according to image information to form a latent image thereon, supply a recording agent (e.g., toner) to the latent image from a developing device to visualize the image, and transfer the image from the photosensitive member to a recording sheet to form the image onto the recording sheet. With the progress of printing, the toner in a toner container coupled to the developing device is consumed.
The toner container, the developing device, the photosensitive member, a charging device, etc., are generally unified into a cartridge, which can be easily detachably mounted to the printing apparatus. When the toner in the toner container is exhausted, the toner container cartridge is replaced by a user.
Some cartridge has a nonvolatile memory that stores information of, e.g., recording agent such as toner, and a serial number for recognition of individual cartridge.
In the meantime, a toner remaining amount is detected in the printing apparatus to display the toner remaining amount on an operation unit and to stop printing when the toner remaining amount is exhausted. However, the toner remaining amount detection requires a time period of several tens seconds to several minutes. In addition, the toner remaining amount detection cannot be frequently performed in the case of printing apparatus where the developing device, photosensitive member, and toner are consumed by the toner remaining amount detection.
Thus, there is known a method for utilizing recording agent information backed up in a nonvolatile memory of the printing apparatus during a time period from when electric power is turned on to when recording agent information is decided (see, for example, Japanese Laid-open Patent Publication No. 2007-128044).
Another method is known in which toner remaining amount is detected when a predetermined number of sheets from several tens to several hundreds have been printed, toner remaining amount information is stored in a memory of a cartridge, and the stored information is referred to during a period when the toner remaining amount detection is not performed.
However, with the method disclosed in Japanese Laid-open Patent Publication No. 2007-128044, even if the cartridge is replaced, the recording agent information backed up in the nonvolatile memory still represents the recording agent information of the old cartridge before replacement, and therefore recording agent information of a new cartridge cannot be utilized.
With the method that stores toner remaining amount information in the memory of the cartridge, the frequency of execution of toner remaining amount detection is low, and therefore the remaining amount information stored in the memory is sometimes old and lacks reliability. If the toner remaining amount detection is not performed upon replenishment of toner, a problem is posed that it takes a long time until the toner remaining amount is detected.